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• 345207-58-1 Acetic acid 3-(3-benzylamino-propyl)-cyclopent-2-enyl ester 
• 192181-83-2 3-(3'-hydroxypropyl)-2-cyclopenten-1-one 
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• 252235-49-7 Toluene-4-sulfonic acid 3-(3-oxo-cyclopent-1-enyl)-propyl ester 
• 345221-63-8 Toluene-4-sulfonic acid 3-(3-hydroxy-cyclopent-1-enyl)-propyl ester 
• 252235-56-6 acetic acid 3-[3-(toluene-4-sulfonyloxy)-propyl]-cyclopent-2-enyl ester 

Relevant academic research and scientific papers

General one-pot reductive gem-bis-alkylation of tertiary lactams/amides: Rapid construction of 1-azaspirocycles and formal total synthesis of (±)-cephalotaxine

Amides are a class of highly stable and readily available compounds. The amide functional group constitutes a class of powerful directing/activating and protecting group for C-C bond formation. Tertiary tert-alkylamine, including 1-azaspirocycle is a key structural feature found in many bioactive natural products and pharmaceuticals. The transformation of amides into tert-alkylamines generally requires several steps. In this paper, we report the full details of the first general method for the direct transformation of tertiary lactams/amides into tert-alkylamines. The method is based on in situ activation of amide with triflic anhydride/2,6-di-tert-butyl-4-methylpyridine (DTBMP), followed by successive addition of two organometallic reagents of the same or different kinds to form two C-C bonds. Both alkyl and functionalized organometallic reagents and enolates can be used as the nucleophiles. The method displayed excellent 1,2- and good 1,3-asymmetric induction. Construction of 1-azaspirocycles from lactams required only two steps or even one-step by direct spiroannelation of lactams. The power of the method was demonstrated by a concise formal total synthesis of racemic cephalotaxine. Four bonds in one pot! Cleavage of two bonds of an amide carbonyl group and replacement by two new C-C bonds can be achieved in one pot under mild conditions by using amide activation with triflic anhydride (Tf2O). A concise formal total synthesis of racemic cephalotaxine has been accomplished by means of this methodology (see scheme; DTBMP=2,6-di-tert-butyl-4-methylpyridine). Copyright

Palladium[0]-mediated aminospirocyclization of tertiary allylic sulfones. Stereospecific construction of the azabicyclic ring system of cephalotaxine

Tertiary allylic sulfones which bear a secondary aminopropyl moiety undergo smooth palladium[0]-mediated spirocyclization. The reaction proceeds via a π-allyl intermediate and the resultant azabicyclic product is formed with net retention of sulfone stereochemistry. The use of tetramethylguanidine as companion base is required for high yielding reactions.

PALLADIUM ASSISTED SYNTHESIS OF 1-AZASPIROCYCLES

A facile, general route to 1-azaspirocycles utilizing a ?-allyl palladium complex in the key cyclization step has been developed.